[PATCH 11/42] state: backend_circular: Read whole PEB

[Sam Ravnborg]

On Fri, Mar 31, 2017 at 09:03:15AM +0200, Sascha Hauer wrote:
> When the circular backend searches for the last page written in the
> eraseblock, it iterates backwards pagewise from the end of the block.
> This is ok for NAND flash, but on NOR flash, which does not have pages,
> the code ends up iterating bytewise backwards, calling into mtd each
> time. This is very time consuming, so optimize this by reading the whole
> eraseblock once and just iterate over the buffer in memory.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
>  common/state/backend_bucket_circular.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/common/state/backend_bucket_circular.c b/common/state/backend_bucket_circular.c
> index 0bce900d0d..53c2aae803 100644
> --- a/common/state/backend_bucket_circular.c
> +++ b/common/state/backend_bucket_circular.c
> @@ -379,26 +379,24 @@ static int state_backend_bucket_circular_init(
>  	int sub_offset;
>  	uint32_t written_length = 0;
>  	uint8_t *buf;
> +	int ret;
>  
> -	buf = xmalloc(circ->writesize);
> +	buf = xmalloc(circ->max_size);
>  	if (!buf)
>  		return -ENOMEM;
>  
> +	ret = state_mtd_peb_read(circ, buf, 0, circ->max_size);
> +	if (ret && ret != -EUCLEAN)
> +		return ret;

We leak buf here.
But ownership of buf is vague.

In one implementation of state_mtd_peb_read() we free buf
in case of errors, but not in all paths.

This is the version of state_mtd_peb_read() outside the

   #ifdef __BAREBOX__

block.

The version of state_mtd_peb_read() inside the

   #ifdef __BAREBOX__

will not free buf, so there ownership is more clear.
But in both cases we may leak buf.

This is as such unrelated to this patch - but noticed while browsing these
patches.

	Sam